Patent GB-385335-A (GB)
Title: Improvements in and relating to steam engines
IPC: F01K19/02
Filed: 1931-06-30
Abstract: 385,335. Steam-power plant. NORTH EASTERN MARINE ENGINEERING CO., Ltd., Wallsend-on- Tyne, and TINDALE, J., 40, Woodbine Road, Gosforth, Newcastleon-Tyne. June 30,1931, No. 18861. [Classes 110 (iii) and 122 (iii).] In a multiple expansion engine, the temperature of the exhaust from one stage is raised before passing to another stage by first expanding the exhaust by passing it through a reducing-valve or turbine and then compressing it in a turbine-driven compressor. The fluid may pass through a superheater. An exhaust-operated turbine may drive mechanical superheaters arranged between the stages. In the construction shown in Fig. 1, the HP exhaust is passed through a throttle or reducing valve t<1> to a rotary compressor c<1> the shaft r of which is operated by a low-pressure, exhauststeam-operated turbine T<1>. A second compressor c<2> acts upon the exhaust steam from the intermediate cylinder MP after passing a reducing-valve t<2>. In a modification only one compressor is used. If the throttle valve is fully open, the pressure in the preceding cylinder is reduced and that in the following cylinder increased. The energy of the turbine then supplements the absolute pressures ; with the throttles in action, the turbine energy effects superheating. In the modification shown in Fig. 2, the MP exhaust operates a turbine T<2> which operates a compressor c<1> which is alsooperated by the LP exhaust-operated turbine T<1>. The exhaust from turbine T<2> passes through a superheated sh heated by waste gases to the compressor c<1>. In a further modification, the LP exhaust operates two turbines, one exhausts to the condenser, and the other to a superheater from which it passes to a compressor or compressors and then to the LP inlet, or LP and MP inlets respectively. A control valve in the LP exhaust determines the proportions of steam passing to the two turbines. A supply for feed heating may be taken from the superheated steam lines. In a further modification, a low-pressure, exhaustdriven turbine drives mechanical superheaters consisting of devices with rotary and stationary blades interposed between the cylinders. The engine may consist of two or more stages. In turbine plants the turbines of the superheaters and compressors may be fitted alongside of the main turbines, or incorporated in the main turbine. In a further modification, a low pressure exhaust turbine drives a compressor arranged between the HP and MP cylinders; the compressed steam passes through a reducing valve to the MP cylinder. In the construction shown in Fig. 6, a heat interchanger C<1> is arranged to operate as a superheater, the exhaust from the turbine T<2> is passed through the superheater to a compressor c<1>. The exhaust from the turbine T<1> is passed through the superheater to the condenser C<3>. In a further modification a portion of the HP cylinder exhaust passes through a reducing valve to a superheater and passes together with the MP exhaust to the LP cylinder. In a modification of this arrangement, a portion of the HP exhaust drives a turbine which drives a compressor, and the turbine exhaust passes through a superheater to the compressor. After compression the steam mixes with the MP cylinder exhaust which passes through the LP cylinder to a condenser or a turbine.